Yarn-treating process



Jan. 21, 1969 BARLQW EI'AL 3,422,516

YARN-TREATING PROCESS Filed Sept. 25, 1967- ATTORNEY United States Patent O 3 Claims ABSTRACT OF THE DISCLOSURE A jet device for treating yarn in various ways is provided. The jet includes a tube defining a confined zone for yarn passage therethrough and wherein the yarn is treated. A fluidic diverting valve having two intersecting output ports opening into the confined zone form part of the apparatus. A source of treating fluid is supplied to an input port of the valve. A tapered block is positioned internally of the block for splitting the fluid alternatingly delivered from the input port to the two output ports. Means are associated with the valve for rapidly oscillating substantially the complete flow of the fluid from one output port to the other output port to intermittenly deliver treating fluid to the yarn as the same moves axially through the zone.

BACKGROUND OF THE INVENTION Yarn jet apparatus of various types utilizing high velocity fluids have been used in the treatment of textile yarns as the same moves axially therethrough. Air jets have been used for transporting yam from one point to another. It is also known to use jets for opening filamentary bundles by disrupting the parallelism of the filaments.

In recent times jets have been used to texture yarn thereby to render the same more voluminous. One operation for doing this, as disclosed in US. 2,783,609, involves passing the yarn under reduced tension through a confined zone provided by a jet in which a fluid, such as air, is introduced under pressure to cause a turbulence such that loops or convolutions are formed in the yarn. Using a slight variation from this just-described operation, one is able to produce a random, three-dimensional crimp in thermoplastic filaments, thereby texturing the same by employing a plasticizing fluid instead of air. Ordinarily steam at a temperature sufficiently high to effect plasticization of the filaments is fed to the jet through which the filamentary material moves.

Another known treatment of filamentary yarn in a fluid jet obviates the need of imparting low twist therein needed for maintaining the continuity of the threadline in various handling operations by causing the individual filaments to become interlaced. Such a yarn interlacing operation is disclosed in US. Patent 2,985,995 and involves passing yarn through a jet under controlled tension. In the jet the filaments are whipped back and forth and become interlaced to form a structure which could be referred to as a false-braid. Even though the yarn may have no twist, it performs in certain textile operations as though twist of several turns per inch were present. Although the interlacing is random, such operation has the drawback that opticaldefects appear in fabric woven from the interlaced yarn. Irregular light reflectances result because large and small groups of the filaments become so erratically entangled that the thread bundle no longer is round along its length, but rather has areas that are ribbon-like. This irregular light reflecting phenomenon is often referred to in the trade as flashes and is quite undesirable from an aesthetic standpoint.

In a slight variation from the interlacing procedure just described synthetic man-made filaments which have been Patented Jan. 21, 1969 drawn can be relaxed to reduce the shrinkage thereof at the same time interlacing is accomplished. Instead of air, steam is often used as the interlacing fluid and induces the relaxation of the yarn. The undesirable flashes also occur in woven fabric made from relaxed and interlaced yarn when known jet apparatus are used.

It has been found in accordance with the present invention that yarn can be eflicaciously treated in a novel yarn jet such that one can produce interlaced yarn exhibiting substantially no flashes. The same apparatus can be used for producing relaxed, interlaced yarn, as well as textured yarn having loops or random three-dimensional crimps or both of these latter characteristics.

SUMMARY OF THE INVENTION Apparatus for extremely rapid intermittent treatment of yarn in a jet of special construction is provided. At a frequency of about 25 cycles per second (c.p.s.) up to 10,000 cycles per second fluid is brought into contact with traveling yarn at closely spaced intervals in a jet apparatus having a confined zone for yarn passage therethrough. A fluidic diverting valve is provided to have two output ports opening into the zone for intermittent fluid contact with the yarn. Means are associated with the valve for rapidly alternating or oscillating substantially the complete flow of the fluid from one output port to the other output port to intermittently deliver treating fluid to the yarn as the same moves through the zone. The fluid paths form an angle from their engagement with the yarn of from at least 10 to 180. Depending upon the selected tension on the yarn in the jet, the yarn can be interlaced or rendered bulky. When a heated fluid is used, relaxation of the yarn can be simultaneously accomplished.

In accordance with the process of the invention, syntheic thermoplastic multi-filament yarn is treated as it moves through a confined zone. A stream of treating fluid is established and delivered to the zone. Substantially complete flow of the fluid is oscillated between two discharge intersecting points at a frequency of about 50 to 10,000 cycles per second (c.p.s.) so that as the yarn moves through the confined zone the yarn is regularly and intermittently treated with the fluid at such frequency. When a textured yarn is produced, one should preferably employ a yarn overfeed to the zone of 10 to 50 percent and steam as the fluid at a temperature of at least 350 F. but below the temperature where filament sticking occurs. When freshly drawn nylon yarn is treated, such yarn will normally be delivered to the confined zone at an overfeed of 4-15%. Using an overfeed of 4-15% with steam of at least C. will result in the formation of relaxed yarn with individually interlaced filaments.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a perspective view of a jet device useful in the practice of the present invention.

FIGURE 2a shows the device in central cross-section taken along line 22 of FIGURE 1 and illustrates the fluid flow from the source thereof to one output port.

FIGURE 2b illustrates the fluid flow having been diverted to the other output port of the device.

FIGURE 3 shows schematically an apparatus assem bly including the jet together with two sets of rolls for controllably delivering the yarn to and from the jet.

FIGURE 4 shows schematically an apparatus assembly for drawing synthetic filaments and immediately thereafter treating the same in the jet to relax and interlace simultaneously the filaments.

THE DISCLOSURE OF THE INVENTION With reference first to FIGURE 1, yarn 10 undergoing treatment passes through a tubular member .11 of the jet apparatus generally denoted by numeral 12. Conduit 13 connects the apparatus to a source of high velocity fluid, not shown, that is discharged into a fluid diverting valve 14. The valve contains a network of internal confined passages for the fluid movement therethrough. The valve has no moving parts; and the control of the high-energy stream of fluid supplied "from conduit 13 as to its intermittent flow through passages 15 and 16 is made by a low-energy stream of fluid oscillating in conduit 17. Valve 14 has two discharge intersecting output ports 18 and 19 opening into tube 11 for fluid contact with the yarn. A solid tapered block 20 splits the fluid delivered from the input port 21 to the output ports. Conduit 17 forms a closed fluid feed back circuit having opposed openings 22 and 23 as seen in FIGURES 2a and 2b. These openings communicate with the flow of fluid between the input port and the tapered block so that oscillating shock waves move in conduit 17 to cause substantially complete flow of fluid to be moved regularly and intermittently from one output port to the other output port.

The abrupt and virtually complete change of fluid flow back and forth from passages 15 and 16 can better be seen by reference to FIGURES 2a and 2b. For most complete switching of the air flow, passages 15 and 16 as well as port 21 are rectangular in cross section. The walls of passages are therefore flat and provide more secure attachment of the fluid to the outer sides of the passages so that more complete flow of the fluid alternately therethrough is attained.

In valve 14 the instant the jet of fluid switches to the upper passage and discharges perpendicularly with respect to the yarn movement, fluid begins to flow through opening 23 and then through conduit 17 providing a generally circular feedback path. This fluid flow is preceded by propagation of a shock wave. When this shock wave front collides with the main jet of fluid, sufficient energy is transferred to cause the main jet to be diverted to the bottom passage 16. The identical action then occurs when the succeeding shock wave travels in the reverse direction through conduit 17. As can be seen, the frequency of oscillation of the jet is a function of the length of feedback path provided by conduit 17 As indicated previously, switching of fluid using this kind of jet has been attained at frequencies over 10,000 c.p.s. A frequency of above 25 c.p.s. is preferred.

It will be noted that both streams of fluid impinge the threadline perpendicularly in the same plane. However, the paths of the fluid discharged from passages 15 and 16 intersect at an angle. Although this angle as formed by the intersection of the extended axes of passages 15 and 16 is not critical, better control on the filament action within the jet is attained when the angle is at least 10 with even better stability being accomplished at or near 180.

In FIGURE 3 yarn 10 is fed to the jet apparatus 12 by a pair of feed rolls 24. A second pair of rolls 25 withdraws the yarn from the jet at a controlled speed. Where a textured yarn is to be produced by the use of the apparatus, an overfeed of the yarn to the jet of about 10% or more up to about is required, thus the filaments in the jet are at all times slack. Where crimps in the yarn provide the texturing, a heated turbulent fluid is supplied to the jet and the yarn should be made of thermoplastic polymer. When loopy yarn is desired to be produced, the yarn should be withdrawn from the jet at an abrupt angle so that the fluid discharge through the bottom of tube 11 acts on the slack filaments to flip loops therein.

Where an interlaced yarn is desired to be produced, the yarn should be maintained under positive tension as it moves through the jet. The tension should be sufl'icient to prevent looping or crimping of the filaments.

In FIGURE 4 apparatus is shown adapted for processing undrawn synthetic thermoplastic multi-filament yarn to produce a drawn, relaxed and interlaced yarn. Feed package 26 provides a source of undrawn yarn which is withdrawn therefrom by feed rolls 27 for delivery to the drawing zone 28 at a metered rate. Snubbing pin 30 can be employed to localize the point of draw of the filament bundle. Draw roll 31 operates at a surface speed considerably greater than the delivery speed of yarn to the zone 28 to provide the desired amount of draw or molecular orientation resulting from such drawing. Draw roll 31 has a step to provide controlled relaxation of the filaments. From the draw zone the yarn passes a plurality of times around separator roll 32 and the portion of roll 31 having the larger diameter to provide sufficient drawing force without appreciable yarn slippage therearound. Next the yarn is moved around roll 33; and on its way to the portion of roller 31 having the smaller diameter the yarn is treated in jet 12. The amount of step down will be dependent upon whether a bulky or interlaced compact yarn is to be provided. Where a crimpy or loopy yarn is desired, the step down will be large enough to provide the slack needed for texturing. When an interlaced yarn is desired, the amount of step down, if any, will be less and is controlled so that the yarn never becomes slack. If heated fluid is used, the yarn may undergo shrinkage; and a step down roll will be needed even though an interlaced untextured yarn is desired since the creeping back of the yarn due to shrinkage will compensate for up to about 12% or more of overfeed and will give rise to the presence of sufficient tension for making an interlaced yarn. Normally nylon yarn will retract 4-l5% during interlacing accomplished immediately after drawing with steam having a temperature of at least 350 F. Upon its return to the lower step of roll 31, the yarn is taken up in an orderly manner. As illustrate-d in FIGURE 4, a ring-traveller takeup device 34 is used for this purpose which ordinarily places a twist in the threadline. When the yarn has been interlaced, it need not be packaged with a twist, since an interlaced yarn already has the handling characteristics of a twisted yarn.

The invention is generally applicable to all man-made yarns. It is particularly useful in treating synthetic multifilament yarn made from linear polyarnides, commonly referred to as nylons, including nylon-66, nylon-6, nylon 7, nylon 6-10, nylon 11, nylon 6/66, nylon 6/66/610, etc. Additional suitable yarns can be made from linear polyesters including polyethylene terephthalate; vinyl polymers including polyvinyl chloride, polyvinylidene chloride and copolymers thereof; acrylonitrile polymers; polyhydrocarbons including polyethylene and polypropylene, etc.

The following examples illustrate specific embodiments of the invention.

Example I Polyhexamethylene adipamide yarn composed of 34 filaments and a drawn denier of 70 is passed through jet 12 using yarn feeding and withdrawing wheels synchronize-d to maintain 0.20 gram per denier tension on the filaments. The yarn speed is 300 yards a minute. Air at ambient temperature moving at /2 sonic velocity enters the jets to treat the yarn moving in tube 11 of the jet. The thus-treated yarn is packaged without twist. It has handling properties comparable to twisted yarn of a few turns per inch. The jet has a conduit 17 designed to provide 60 c.p.s. oscillation of the air from one outlet to another. The interlacing of the filaments follows a systematic pattern but is so finely dispersed along the threadline that no optical defects appear in fabric woven therefrom.

When conduit 17 is removed or plugged to prevent the oscillation of the air flow, there is good interlacing of the filaments; but the yarn does not have a uniformly round cross section along its length. Optical defects appear in fabric woven therefrom.

The same observation of no optical defects is made with polyethylene terephthalate 70 denier 34 filament yarn, when likewise treated in the jet as described in this example.

Example II Drawn polyhexamethylene adipamide yarn of 70 denier 34 filament count is passed through jet 12 at 200 yards per minute with overfeed of 25%. Steam at 200 C. is introduced to jet 12 and impinged on the yarn at a frequency of 75 c.p.s. The resulting yarn has a bulky appearance with the individual filaments thereof showing a random three-dimensional crimp.

Example III Drawn polyhexamethylene adipamide yarn of 70 denier 34 filament count is passed through jet 12 with a 20% overfeed. The yarn speed is 200 yards a minute. Air ambient temperature at /2 sonic velocity is the treating fluid which is switched at 60 c.p.s. As the yarn leaves the jet, it is directed at right angles therefrom. The resulting yarns have a multitude of loops along their length.

Example IV Polyhexamethylene adipamide yarn of 13 filaments is drawn to a final denier of 40 using the apparatus of FIGURE 4. The yarn moves around the draw roll 31 at a speed of 395 yards per minute, to the jet 12 and around the lower step of roll 31 providing a yarn overfeed of 12% to the jet. Superheated steam at 150 C. moves through jet 12 and impinges on the yarn at a frequency of 75 c.p.s. The resulting yarn is relaxed and interlaced. No flashes are observed in the interlaced yarn.

Numerous advantages are provided by the present invention. A novel and useful jet for treating filaments is disclosed. The treating fluid is intermittently applied to the filaments at extremely high frequencies with the result that any non-uniformities inherent in the treating processes are so fine and well dispersed that they are not apparent. At low frequencies novel effects can be obtained in the treated yarn. The jet apparatus has no moving parts and can be made of practically any material that can be cast, molded, :machined or other-wise shaped. The diverting valve switches the fluid flow quickly and almost completely with little or no vibration. Furthermore, the jet requires very little maintenance. The jet can be used for a variety of purposes including bulking yarn, interlacing yarn, re-

laxing yarn, interlacing and relaxing yarn simultaneously. Other textile uses are readily apparent.

What is claimed is:

1. A yarn treating process comprising:

(a) moving synthetic thermoplastic continuous multifilament yarn through a confined zone;

(1)) establishing a stream of treating fluid delivered to said zone;

(c) oscillating substantially complete flow of the fluid between two discharge intersecting points at a frequency of about 5040,000 cycles per second so that as the yarn moves through the confined zone the yarn is regularly treated with the fluid from each of the discharge points alternately, as the fluid is oscillated between the two discharge points at such frequency; and

(d) impinging the discharged fluid directly onto the axis of the yarn moving through the confined zone to disrnpt the parallelism of the filaments of the yarn so that the resultant yarn is textured or interlaced.

2. The process of claim 1 wherein the yarn is delivered to the confined zone at an overfeed of 10-50% and the fluid is steam at a temperature of at least 350 P. so that the yarn is textured.

3. The process of claim 1 wherein freshly drawn nylon yarn is delivered to the confined zone at an overfeed of 4-15 and the fluid is steam at a temperature of at least C. so that the yarn is relaxed and individual filaments thereof are interlaced.

References Cited UNITED STATES PATENTS 3,116,588 1/1964 Breen et a1. 5734 MERVIN STEIN, Primary Examiner.

IRA C. WADDEY, JR., Assistant Examiner.

US. Cl. X.R. 

